The present invention relates to displaying traffic information on a representation or display of a portion of a road network on a display screen.
Vehicle drivers, as well as others, rely on timely and accurate traffic information. Traffic information can be delivered in various ways, such as by audio messages or visually. One way to present traffic information visually is on a map display. The visual presentation of traffic information provides the advantage that a user can quickly grasp relevant information about traffic congestion and compare traffic conditions on different routes.
There are various sources that provide traffic information visually. For example, traffic information is provided visually from Internet web sites. Traffic information is also provided visually on devices with wireless communications capabilities, such as mobile phones, personal digital assistants, personal navigation systems, or in-vehicle navigation systems.
One conventional type of map display that includes traffic information is shown in FIG. 1. In FIG. 1, a map 10 of a geographic region 12 is rendered on a display 14. The display 14 may be connected to or part of a personal computer, a mobile phone, a personal digital assistant, a personal navigation system, or other electronic device. This map 10 shows part of the road network located in the region 12. Traffic conditions on some of the roads are indicated on the map 10. In this figure, different traffic conditions are indicated by different colors. Along portions 16 of roads where traffic is flowing relatively quickly, e.g., 40 mph or higher, the road is depicted in a selected color, e.g., green. Along portions 18 of roads where traffic is flowing slower, e.g., 20-40 mph, the road is depicted in a different selected color, e.g., yellow. Along portions 20 of roads where traffic is flowing even more slowly, e.g., less than 20 mph, the road is depicted in another selected color, e.g., red.
Another conventional way to indicate traffic on a map display is to show numbers adjacent to a selected roadway where the numbers indicate the average vehicle speed along the roadways.
Although these ways of indicating traffic conditions along roads are useful, there exists room for improvements. For example, using different colors may make the map harder to read or understand. Where numbers indicating average vehicle speeds are used, they may be hard to read or interpret. Accordingly, there is a need for further ways to indicate traffic conditions to a user.